package day0811T;

import java.util.Scanner;

/**
 * @Author:galaxy_yan
 * @Date: 2022/8/14
 * @Time: 10:11
 * @Description
 * 作业标题(1687)
 * 斐波那契数列  递归
 */
public class text4T {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();

        System.out.println(fibonacci(n));

    }
    public static int fibonacci(int n){
        if(1==n||2==n){
            return 1;
        }
        return fibonacci(n-1)+fibonacci(n-2);
    }
}
